Multimedia Computer System and Method

ABSTRACT

A multimedia computer system and method is disclosed. A medium device of the computer system, like an optical disc loader, has a built-in function of multimedia decoding for supporting the computer system to work under a normal mode and a playback mode. In the normal mode, the medium device does not decode, and north/south bridges of the computer arrange data exchange and access between the medium device, a CPU, and a memory of the computer system. In the playback mode, the medium device performs multimedia decoding itself for obtaining video data from the medium, and the video data are sent to a display of the computer system by the north bridge. Therefore, in this playback mode, other circuits like the south bridge, CPU and memory can be powered down to an idle status, and a low power consumption multimedia broadcast is realized.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional Application No.60/630,533, filed Nov. 22, 2004, and included herein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a multimedia computer system andmethod, and more particularly, to a multimedia computer system andmethod capable of supporting a low power consumption multimedia playbackmode.

2. Description of the Prior Art

In this modern information age, all documents, figures, data and videoinformation can be transmitted, processed and stored in a format ofelectronic signals. It is especially popular for use with multi-mediadata of images and sounds, which can be recorded in a vivid manner, ortransmitted as a dynamic message. This application is now very popularand being commonly used by the public. In generally, a userelectronically manages static documents, figures and data via thecomputer system; thus in order to satisfy the general public's need formultimedia, an important issue for manufacturers to consider how tocombine dynamic multimedia broadcast functions more effectively with thecomputer system.

In general, whereas the data capacity of a dynamic multimedia videomessage is considerably large, the video message is coded and compressedin a fashion compliant to a multimedia format to become multimedia dataso that this is more convenient for the user to store, transmit andprocess. After coding, the multimedia data is usually stored in anon-volatile storage medium such as a compact disc. The compact discoffers the consumer a low cost medium that stores a large amount ofdata. Therefore, when the video of the multimedia data is beingbroadcast, the multimedia data of the storage medium is first beingaccessed and then decoded to obtain image and audio data of themultimedia data. In doing so, the image data is being broadcast througha display unit, and the audio data is being broadcast through aloudspeaker such that the user can experience the dynamic visual andsound information of the multimedia data. Modern technology affords manymultimedia formats, such as: Motion Picture Experts Group's (MPEG)MPEG1, MPEG2 and MPEG4 being utilized for performing code andcompression of video data, and a Digital Versatile Disc (DVD) utilizedas it has a large high density storage volume for storing multimediadata.

As known to those skilled in the art, a common computer system includesa central processing unit (CPU), and a chipset with a north bridge and asouth bridge and is utilized for supporting a memory of the CPU. Inorder to support multimedia broadcast, the computer system also includesa display unit and a loudspeaker 68 where the CPU can perform figurecalculations and data processes, The south bridge is utilized to managedata access of each input and output peripheral device (i.e., includingthe medium device), the north bridge is coupled with the CPU, the southbridge and the memory for managing data transmission among the circuits,and the image data is transmitted to the display unit to be displayed.The chipset also includes an audio codec circuit (for example, an AC97codec, an audio coding circuit that is AC97 compliant) coupled to thesouth bridge that is able to execute a modulation on the audio signal tosignal for broadcasting the corresponding sound on the loudspeaker.

When the multimedia broadcast function is combined with the computersystem, the conventional technology utilizes the medium device installedwithin the computer system to access multimedia data of the storagemedium, and then utilizes the CPU to perform decode of the multimediadata to recover the video information of the multimedia data. The mediumdevice, utilized for accessing a storage medium, does not have adecoding function. It is only capable of accessing decoded (i.e.,compressed) multimedia video data, and the CPU is required to performmultimedia decoding. For the CPU to perform decoding, the CPU has toaccess the medium device, and this requires the south bridge and thenorth bridge of the chipset to perform bridging; furthermore, when theCPU is performing decoding, the CPU also requires support from thememory, thus the north bridge of the chipset must perform bridging inbetween the CPU and the memory. Image data decoded from the multimediadata by the CPU is stored within the memory, and the image data is thentransmitted to the display unit of the computer system by the northbridge to be displayed on the display unit; and the decoded audio datais then transmitted from the memory, the north bridge and the southbridge to the audio codec of the chipset, lastly the audio data is thenbroadcast through the loudspeaker 68 of the computer system.

In another words, when the conventional technology performs a multimediabroadcast, the CPU, the memory, the south bridge and the north bridgemust be fully functional in order to realize multimedia broadcast. Inthis way, the power consumption is high. When a notebook computer systemis utilized to realize the conventional multimedia broadcast technology,the high power consumption on the battery of the computer system willgreatly reduce the operation time for the computer system.

SUMMARY OF THE INVENTION

The claimed invention provides a modified multimedia broadcasttechnology to realize a low power consumption multimedia broadcast in acomputer system.

The claimed invention discloses a computer system capable ofbroadcasting multimedia data, the computer system comprises a mediumdevice having a front-end and a back-end, wherein the front-end isutilized for accessing multimedia data from a storage medium, and theback-end is utilized for decoding a corresponding image data from themultimedia data if the multimedia data from the storage medium accessedby the front-end is compliant with a preset multimedia format, and achipset coupled to the medium device for transmitting the image dataobtained from decoding by the back-end to a display unit for displayingwhen the computer system operates in a default playback mode.

The claimed invention discloses a medium device capable of connecting toa computer system, the medium device comprises a medium module forloading a storage medium, a front-end for controlling the medium moduleand accessing a multimedia data of the storage medium, and a back-endfor decoding the multimedia data to obtain a corresponding image datawhen the medium device is operating in a default playback mode, aprimary bridge of the computer system for displaying the image datawithin the computer system.

The claimed invention discloses a computer system capable of performingmultimedia broadcast and coupled to a medium device, the computer systemcomprises a display unit for broadcasting an image data decoded by aback-end within the medium device, and a primary bridge coupled to thedisplay unit for transmitting the image data decoded by the back-end ofthe medium device to the display unit.

The claimed invention discloses a computer system capable ofbroadcasting multimedia data and coupled to a medium device, thecomputer system comprises a display unit for displaying an image data; aprimary bridge coupled to the medium device and the display unit fortransmitting the image data decoded by a back-end of the medium deviceto the display unit to be displayed when the computer system isoperating in a default playback mode; a secondary bridge coupled to themedium device and the primary bridge for transmitting the image datadecoded by a front-end of the medium device to the primary bridge whenthe computer system is not operating in the default playback mode; theprimary bridge transmits the image data to the display unit; and a CPUcoupled to the primary circuit for controlling operations of thecomputer system, when the computer system is operating in the defaultplayback mode, the CPU stops operating, and when the computer system isnot operating in the default playback mode, the CPU operates.

The claimed invention discloses a method of broadcasting multimedia dataon a computer system, the computer system comprises a medium device anda computer, the medium device is coupled to the computer through aconnecting port, wherein the medium device comprises a back-end and afront-end, and the computer comprises a primary bridge, a secondarybridge, a CPU and a display unit, the method comprises determiningwhether the computer system is operating in a default playback mode; theback-end within the medium device decoding the multimedia data if thecomputer system is operating in the default playback mode, and theprimary bridge of the computer transmitting the decoded multimedia datato the display unit of the computer to be displayed; and the front-endwithin the medium device transmitting the multimedia data from thesecondary bridge of the computer to the primary bridge if the computersystem is not operating in the default playback mode, and the front-endtransmitting the multimedia data to the display unit of the computer viathe CPU to be displayed.

The claimed invention discloses a method of broadcasting multimedia dataon a computer system, the computer system comprises a medium device anda computer, the medium device is coupled to the computer through aconnecting port, wherein the medium device comprises a back-end and afront-end, and the computer comprises a primary bridge and a displayunit, the method comprises the back-end of the medium device decodingthe multimedia data; and the primary bridge of the computer transmittingthe decoded multimedia data to the display unit of the computer to bedisplayed.

These and other objectives of the present invention will no doubt becomeobvious to those of ordinary skill in the art after reading thefollowing detailed description of the preferred embodiment that isillustrated in the various figures and drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a functional block diagram of a conventional computersystem.

FIG. 2 illustrates a flowchart of the computer system 10 of FIG. 1executing a conventional boot sequence.

FIG. 3 illustrates a functional block diagram of a computer systemaccording to an embodiment of the present invention.

FIG. 4 illustrates a diagram of the computer system of FIG. 3 operatingin a normal mode.

FIG. 5 illustrates a diagram of the computer system of FIG. 3 operatingin a playback mode.

FIG. 6 illustrates a flowchart of the computer system of FIG. 3executing a boot sequence.

FIG. 7 illustrates a diagram of the computer system of FIG. 3 accordingto an embodiment of the present invention.

FIG. 8 illustrates a diagram of the bus of FIG. 7 according to anembodiment of the present invention.

FIG. 9 illustrates a diagram of the medium device of FIG. 3 becoming anindependent broadcasting device.

DETAILED DESCRIPTION

Please refer to FIG. 1. FIG. 1 illustrates a functional block diagram ofa conventional computer system 10. The computer system 10 includes acomputer 20 and a medium device 30 for accessing storage medium. Thecomputer 20 includes a central processing unit (CPU) 12, a memory 14, adisplay unit 32, a chipset 40, loudspeaker 28 and a control interface26. The CPU 12 is capable of executing programs and algorithmiccalculations, processing data, and controlling the main operation of thecomputer system 10; the memory 14 is utilized for temporarily storingprogram codes, data, and figures required by the CPU 12 duringoperation. The display unit 32 is utilized for displaying graphicpictures, and the loudspeaker 28 broadcasts sound. The control interface26 is then utilized for receiving control operations of a user such as akeyboard, a mouse, a touch pad, or other indicating devices. The mediumdevice 30 acts as a peripheral of the computer system 10 and is coupledto the chipset 40. The chipset is located among the medium device 30 (orother peripheral devices), the memory 14 and the CPU for bridging datatransmission of these circuits.

In a more detailed explanation, the chipset 40 can include a northbridge 16, a south bridge 18, an audio codec circuit 22, and amicro-controller 24. The south bridge 18 is coupled with each peripheraldevice (e.g., the medium device 30) and the north bridge to manage datatransmission between each peripheral device and the north bridge 16. Thenorth bridge 16 is coupled with the CPU 12, the memory 14 and the soundbridge 18 among which the north bridge 16 manages data transmissionamong the three components. The peripheral device (e.g., the mediumdevice 30) is capable of exchanging data with the CPU 12 and the memory14 via the south bridge 18 and the north bridge 16. Furthermore, thenorth bridge 16 itself can also be integrated with graphic processingfunctions (e.g., the 2-D or 3-D graphic processing) to control thegraphic picture displayed on the display unit 32. The micro-controller24 is coupled to the control interface 26 to provide the correspondingoperation signal according to the control operation of the user to betransmitted to the CPU 12 via the south bridge 18 and the north bridge16 so that the CPU 12 can control the operation of the computer system10 according to the control operation of the user. When the computersystem 10 according to an electronic audio signal broadcasts acorresponding sound, the audio signal is transmitted to the audio codeccircuit 22 via the south bridge 18, and the audio codec circuit 22(e.g., an AC97 codec, an audio coding circuit that is AC97 compliant) isable to execute a suitable modulate code on the audio signal and thecorresponding sound is broadcast through the loudspeaker 28.

In the prior art, a medium module 36 and a server circuit 38 areinstalled within a medium device 30 for accessing storage medium. Themedium module 36 is utilized for containing a storage medium and allhardware for accessing storage medium, the server circuit 38 then isable to control the operations of the medium module 36 to access data onthe storage medium via the medium module 36. For example, the mediumdevice 30 can be a CD player and the storage medium accessed is thecompact disc; the medium module 38 can include rotating motor, laserhead, etc. for accessing the compact disc, and the server circuit 38 cancontrol the medium module 38 to access data from the compact disc. Thedata accessed by the server circuit 38 is transmitted to the computer 20via the south bridge 18. When the conventional computer system 10 ofFIG. 1 broadcasts multimedia data in the storage medium to realize avideo multi-media broadcast function, the situation is described asfollows. Firstly, the server circuit 38 of the medium device 30 can readthe coded, or yet to be decoded, multimedia data from the storagemedium; but as the conventional medium device 30 does not have adecoding function, the calculation function of the computer 20 isrequired for decoding. Hence the medium device 30 temporarily stores themultimedia data to be decoded to the memory 14 via the south bridge 18and the north bridge 16 so that the CPU 12 (or the image processingfunction of the north bridge) can decode the coded multimedia data intocorresponding image data and audio data. The decoded image data istransmitted to the display unit via the north bridge 16 to be displayed;the audio data is then transmitted to the audio codec circuit 22 via thesouth bridge 18 and the corresponding sound is broadcast through theloudspeaker 28.

In the above-mentioned, when the conventional computer system 10 isperforming a multimedia broadcast, other than the medium device 30, theconventional computer system 10 still requires the CPU 12, the memory14, the south bridge 18 and the north bridge 16 to realize themultimedia broadcast, therefore the conventional computer system 10requires high power consumption. As known to those skilled in the art,the south bridge 18 also includes sub-circuits such as an interruptcontroller, a direct memory access (DMA) controller and other types ofbus controller (e.g., the medium device 30 and the south bridge arecoupled through a bus, and a controller of the bus is installed on thesouth bridge). The north bridge 16 also includes a bridging controlcircuit (e.g., controlling data transmission among the CPU 12, thememory 14 and the south bridge 18) and sub-circuit like image processingcircuit. However, from the above-mentioned, when the conventionalcomputer system 10 is utilized to perform the multimedia broadcast, thesub-circuits of the south bridge 18 and the north bridge 16 are alsorequired to operate so that the CPU 12, and the memory 14 can completethe multimedia decoding calculation together. Although full operation ofeach circuit can maximize the full potential of the whole operationfunction, but in some applications, the user may only want todemonstrate multimedia data and multimedia broadcast, therefore there isno requirement to utilize all the functions of the computer system; itis only a waste of power and resource if the computer system operates atnormal.

FIG. 2 illustrates a flowchart 100 of the computer system 10 of FIG. 1executing a convention boot sequence. The flow 100 includes thefollowing steps:

Step 102: a computer system usually has a switch for power on; when auser presses the switch, the computer system triggers power andactivates the flow 100;

Step 104: the computer system 10 performs a power-on self test (POST);if the test is not completed, then terminate the flow 100; if the testis successful, then proceed to step 106;

Step 106: search and execute basic I/O system (BIOS) of each assistancecircuit, for example, search and execute the BIOS of the imageprocessing circuit, furthermore, for other assistance circuits such asan Internet interface circuit that may have a BIOS, the BIOSs can alsobe executed in this step;

Step 108: execute memory test to test the memory; if the test fails,display an error message and terminate the flow 100; if the test issuccessful, then proceed to step 110;

Step 110: set operation parameter of each device in the computer system;

Step 112: detect and set plug and play device

Step 114: search for a boot disk, which is a storage medium that storesan operating system program code; if the boot disk is not available (theoperating system for booting cannot be found on each storage medium),then display an error message and terminate the flow 100; if search issuccessful, proceed to step 116;

Step 116: load the operating system through the boot disk so that theuser can control the computer to perform operations.

From the conventional boot sequence 100, the conventional computersystem 10 consumes more power when supporting multimedia broadcast; alsobefore performing the multimedia broadcast, more time is actuallyrequired to execute the long boot sequence 100. The boot sequence 100ensures the computer system can maximize its full operation functions,however, when the user requires only multimedia broadcast, the computersystem 10 is still required to carry out time consuming steps likeloading the operating system before supporting the multimedia broadcast,which causes inconvenience for the user.

In order to overcome inconvenience of the convention computer system 10of FIG. 1 and FIG. 2 during the multimedia broadcast, the presentinvention provides a preferred computer system architecture so that thecomputer system of the present invention can realize a low powerconsumption multimedia broadcast. In the present invention, the mediumdevice itself has a multimedia data decoding function, and the mediumdevice can combine with the chipset of the computer system to realize amode switching mechanism thereby providing the computer system with thecapable of operating at a normal mode and also at a low powerconsumption multimedia playback mode; at the playback mode, the mediumdevice itself is capable of decoding the coded multimedia data intoimage and audio data, and the medium device utilizes the display unitand the loudspeaker of the computer system directly to realize themultimedia broadcast. Therefore in the playback mode, the computersystem of the present invention is not required to perform decodingcalculations, and the functions of the CPU, the memory, the south bridgeand the north bridge can be idle (not operating) which the powerconsumption is effectively lowered during multimedia broadcast. Pleaserefer to FIG. 3. FIG. 3 illustrates a functional block diagram of acomputer system 50 according to an embodiment of the present invention.The computer system 50 includes a computer 60 (e.g., a mainframe) and amedium device 70 (or a plurality of medium devices) acting as aperipheral device. A central processing unit 52, a memory 54, a displayunit 72 capable of displaying graphic images, a loudspeaker 68 capableof broadcasting sound are installed in the computer system 50, a controlinterface 66 for receiving control operation of a user, and a chipset 80coupled to each circuit of the above-mentioned.

In the computer 60, the CPU 52 is capable of executing programs andalgorithmic calculations, processing data, and controlling the mainoperations of the computer system 50; the memory 54 is utilized fortemporarily storing program codes, data and figures required by the CPU52 during operation. The display unit can be an LCD display or a CRTdisplay. The control interface 66 can include input devices such as akeyboard, a mouse, a touchpad, or even a remote control interface. Forexample, a wireless receiver can be installed on the control interface66 so that the user can utilize the wireless remote controller totransmit wireless remote control signal to the control interface 66.When the user is operating on the control interface 66, the chipset canprovide corresponding control signals according to the control operationof the user.

On the other hand, a medium module 74, a front-end 76 and a back-end 78are installed within the medium device 70. The medium module 74 isutilized for loading a storage medium and including all hardware foraccessing a storage medium. The front-end is a server circuit forcontrolling the operation of the medium module 76 and accessing datastored on the storage medium via the medium module 74. In order torealize the present invention, the medium device 70 of the presentinvention further installs a back-end 78 having a multimedia datadecoding function. The back-end 78 can perform multimedia data decodingin a preset multimedia format to obtain corresponding video and audiodata. For example, if there is coded multimedia data stored in thestorage medium in the medium module 74, the front-end 76 then cancontrol the medium module 76 and access the coded multimedia data; ifthe multimedia format of the multimedia data is compliant to thedecoding format of the back-end 78, then when the back-end 78 operates,the back-end 78 then decodes the multimedia data into correspondingvideo and audio data. In this embodiment of the present invention, themedium device 70 can be a disc player for accessing an optic storagemedium (e.g., a compact disc); the medium module 74 can also includerotating motor, laser, etc for accessing the optic storage mediumhardware, and the front-end 76 then can control the medium module 74 toaccess data from the optic storage medium. The back-end 78 can be aMPEG1, MPEG2 or/and MPEG4 multimedia decoding circuit to decode MPEG1,MPEG2 and/or MPEG4 multimedia data.

The medium device 70 acts as a peripheral device of the computer device50 and is coupled to the chipset 80 so that the chipset 80 can performbridging with the medium device 70 (and other peripheral devices andstorage devices), the memory 54, the CPU 52, the display unit 72, theloudspeaker 68 and the control interface 66. In the present invention,the chipset 80 can combine with the medium device 70 to realize aswitching mode mechanism so that the computer system is capable ofswitching operation to a normal mode and a playback mode.

When the computer system 50 of the present invention operates at thenormal mode, the CPU 52 and the memory 54 will operate normally, thechipset then performs bridging with the CPU 52, the memory 54 and themedium device 70 and manages data transmission among the circuits anddevices. The back-end 78 of the medium device 70 remains idle (nodecoding to be performed) so that the medium device 70 only accesses theoriginal data of the storage medium via the front-end 76. In anotherwords, the chipset 80 can access the storage medium in the medium devicevia the front-end 76 according to the control of the CPU 52.Furthermore, when the user is operating on the control interface 66, thechipset 80 can provide corresponding control signals so that the CPU 52is under the control of the control signal. Hence under the normal mode,the computer system 50 can complete its operation function normally.

When the computer system 50 of the present invention operates in theplayback mode to perform multimedia broadcast, the front-end 76 of themedium device 70 accesses multi-media data from the storage medium, andthe back-end 78 operates and decodes the multimedia data intocorresponding image data and audio data; the chipset 80 then transmitsthe image data decoded by the back-end 78 to the display unit to bedisplayed, and the audio data is broadcast through the loudspeaker 68 assound. As the back-end 78 is in charged of decoding the multimedia,hence in the playback mode, the CPU 52 is capable of operating at a lowpower consumption mode in an idle status. Similarly, the memory 54 canalso stop operating; the chipset 80 itself is not required to support afull bridging function (for example, it is not required to bridge theCPU 52 and the memory 54). Therefore, in the playback mode of thepresent invention, the power consumption of the computer 60 is greatlyreduced and yet the multimedia broadcast function is realized.Alternately, in the playback mode, the control of the control interface66 by the user is converted to control signal by the chipset 80, and thecontrol signal is then transmitted to the medium device 70 such that thefront-end 76 and the back-end 78 of the medium device 70 can becontrolled by the control signal, therefore the user can control themultimedia broadcast.

To further describe the application of the present invention, pleaserefer to FIG. 4 and FIG. 5; a continuation from the embodiment shown inFIG. 3, FIG. 4 and FIG. 5 illustrate situations of the computer system50 operating in a normal mode and a playback mode. As shown in FIG. 3through FIG. 5, a north bridge 56 (which is a primary bridge), a southbridge 58 (a secondary bridge), an audio codec circuit 62, and amicro-controller 64 can be installed on the chipset 80. The north bridge56 is coupled with the CPU 52, the display unit 72 and the memory 54;the south bridge 58 is then coupled to the north bridge 56 and themedium device 70 (and other peripheral devices). The north bridge 56 canbe integrated with a 2D/3D image processing function, and can include avideo port 82 (which can be a VIP video port) for receiving image data(e.g., image data that is compliant to CCIR656 format), and the imageprocessing function of the north bridge 56 allows the video port 82 toreceive the image data to be displayed on the display unit 72. Themicro-controller 64 is coupled to the control interface 66 for providinga corresponding control signal according to the control operationreceived by the control interface 66. The audio codec circuit 62 (forexample an AC97 codec, an audio coding circuit that is AC97 compliant)is able to execute a modulation on the electronic audio signal to signalfor broadcasting on the loudspeaker 68 so that the loudspeaker 68 canbroadcast the corresponding sound according to the electronic audiosignal.

As shown in FIG. 4, when the computer system 50 is operating in thenormal mode, the back-end 78 of the medium device 70 can stop operating(represented in the dotted line), and only the front-end 76 and thesouth bridge 58 maintains a data path (represented to realize the datapath), and the south bridge 58 can perform bridging with the northbridge 56 and the front-end 76. In other words, when the computer 60accesses the storage medium, the south bridge 58 transmits the dataaccessed by the front-end 76 to the north bridge 56, and the northbridge 56 performs bridging with the CPU 52, the memory 54 and the southbridge 58 to control the data transmission among the circuits. Thus thedata of the south bridge 58 is transmitted to the memory 54 and/or theCPU 52. If a graphic image is required to be displayed or sound isrequired to be broadcast during the period when the CPU 52 is operating,the north bridge 56 performs the image processing according to therequest of the CPU 52 such that the graphic image is displayed on thedisplay unit 72; for example, the display unit 72 can include a signaltransmitter (e.g., a low-voltage differential signal (LVDS)) and aliquid crystal panel, and the north bridge 56 transmits the image datato the signal transmitter, and the signal transmitter controls theliquid crystal panel to display the corresponding image. Otherwise, theaudio signal is transmitted to the audio codec 62 via the south bridge58 and broadcast through the loudspeaker 68. Furthermore, in the normalmode, the control of the user is feed back to the micro-controller 64via the control interface 66, and the micro-controller 64 transmits thecorresponding control signal to the south bridge 58 so that the southbridge 58 via the north bridge puts the CPU 52 under the control of thecontrol signal. In the normal mode, each circuit device of the computersystem 50 can be fully functional to support all the computer functions;and the medium device 70 can support each medium access function via thefront-end 76, such as programmed I/O of the CPU 52, or direct memoryaccess (DMA) function of the south bridge 58.

When the computer system 50 of the present invention operates in theplayback mode, the situation is as illustrated in FIG. 5. When thecomputer system 50 operates in the playback mode and broadcastsmultimedia data from the storage medium, the back-end 78 of the mediumdevice 70 can be activated for multimedia decoding functions. Thefront-end 76 reads multimedia data from the storage medium, and theback-end 78 then can decode the multimedia data into corresponding imagedata and audio data. The mode switching mechanism of the medium device70 and the chipset 80 allows the image data to be directly transmittedto the video port 82 of the north bridge 56, and the image processingfunction of the north bridge 56 transmits the image data to the displayunit 72 to be displayed. Otherwise, the image processing function of thenorth bridge 56 can also perform a basic image processing (e.g.,scaling, deinterlacing) on the image data first, and then display theimage data on the display unit 72. Similarly, the mode switchingmechanism of the medium device 70 and the chipset 80 allows the audiosignal decoded by the back-end 78 to be transmitted to the audio codec62 to be broadcast through the loudspeaker 68. Furthermore, after themicro-controller 64 feeds back the user's control and generates acontrol signal, the mode switching mechanism allows the control signalto be transmitted to the medium device 70 so that the front-end 76 andthe back-end 78 of the medium device 70 can be controlled by the controlsignal, therefore the user can control the multimedia broadcast.

In other words, in the playback mode, the back-end 78 controls themultimedia broadcast of the computer system 50, and the user can stillcontrol the multimedia broadcast utilizing the original controlinterface 66 of the computer system 50 (including start, stop, pause,forward, rewind, previous/next chapter, etc). The back-end 78 itself hasan on-screen display (OSD) function for reflecting the status of themultimedia broadcast via the display unit 72 (such as the broadcastingprogress). Other than utilizing the control interface 66 of the computer60 to control the multimedia broadcast, the medium device 70 itself canalso have a specialized control interface for the user to directlycontrol the back-end 78.

In FIG. 5, when the computer system 50 of the present invention isoperating in the playback mode, the back-end 78 performs the multimediadecoding function, thus the calculation function of the computer 60 isnot required to perform the multimedia decoding. Hence in the playbackmode, the CPU 52 can be idle or stop operating; the related memory 54can also stop operation, and the north bridge 56 can also terminate itsbridging function for transmitting data among the CPU 52, the memory 54and the south bridge 58. The south bridge 58 can further terminate eachfunction: the south bridge 58 can terminate each bus control function;the south bridge 58 can terminate the bridging with the medium device 70and the north bridge 58 (as shown in FIG. 5, the image data/audio dataof the medium device 70 is directly transmitted to the north bridge56/audio codec 62 and the bridging of the south bridge 58 is notrequired), functions like interrupt control and DMA can also terminate.As the bridging function of each of the CPU 52, the memory 54, the southbridge 58 and the north bridge 56 stops operating (or enters into a lowpower consumption idle status), therefore during the multimediabroadcast, the power consumption of the computer system 50 of thepresent invention can be greatly reduced to realize a low powerconsumption multimedia broadcast function.

In order to control the switch between the normal mode and the low powerconsumption playback mode of the computer system, the present inventioncan prompt the user during the boot sequence to perform a modeselection. Continuing with the example from FIG. 3 through FIG. 5,please refer to FIG. 6. FIG. 6 illustrates a flowchart 200 of thecomputer system 50 of the present invention executing a boot sequence.The flow 200 includes the following steps:

Step 202: power on, the computer system 50 draws power and activates theflow 200;

Step 204: the computer system 50 performs a power-on self test (POST);if the test is not completed, then terminate the flow 200; if the testis successful, then proceed to step 206;

Step 206: search and execute basic I/O system (BIOS) of each assistancecircuit, for example, search and execute the BIOS of the imageprocessing circuit, furthermore, for other assistance circuits such asan Internet interface circuit that may have a BIOS, the BIOSs can alsobe executed in this step;

Step 208: execute memory test to test the memory; if the test fails,display error message and terminate the flow 200; if the test issuccessful, then proceed to step 209;

Step 209: determine a mode of operation for the computer system; if anormal mode is selected, proceed to step 210, if a playback mode isselected, proceed to step 218; in this step the present inventionprompts a user on the display unit 72 to proceed with the mode selection(FIG. 3) to determine which mode the computer system is enteringaccording the user's control on the control interface 66, for examplethe prompts on the display unit 72 can be: pressing the F key on thecontrol interface 66 to enter into the normal mode, or press the P keyon the control interface 66 to enter into the playback mode, thenproceed to step 210 or step 208 after the key is pressed by the user;furthermore the present invention can also preset a mode which thecomputer system will enter after a predetermined period of time whilewaiting for the user to decide whether to enter into a specific mode, ifuser input is not forthcoming within the predetermined period of timethen the computer system 50 enters the preset mode; for example inexecuting this step, the computer system 50 can be preset to enter intothe normal mode, and the user will be prompted; if the user wants toenter into the playback mode, the user can press a DEL key, and there isa 10 second countdown, if within this 10 seconds the DEL key is notpressed, the computer system 50 enters into the preset normal mode andproceeds to step 210; otherwise, if the user presses the DEL key withinthe countdown time, the computer system enters into the playback modeand proceeds to step 218.

If the user decides to let the computer system 50 to enter into thenormal mode, the computer system 50 executes the steps 202, 204, 206 and208 accordingly and performs a normal boot sequence, the normal bootsequence includes the following steps:

Step 210: set operation parameter of each device in the computer system;

Step 212: detect and set plug and play device;

Step 214: search for a boot disk, which is a storage medium/mediumdevice that stores an operating system program code; if the boot disk isnot available (the operating system for booting cannot be found on eachstorage medium), then display an error message and terminate the flow200; if search is successful, proceed to step 216;

Step 216: load the operating system through the boot disk so that theuser can control the computer to perform operation.

On the other hand, if the user decides to perform multimedia broadcastand allows the computer system 50 to enter into the playback mode, thecomputer system 50 continues to execute the following steps after step209:

Step 218: the CPU 52 sets the configuration of the north bridge 56 (FIG.5) to shut down unnecessary functions, as known from FIG. 5 and otherrelated discussions, in the playback mode, the medium device 70 of thepresent invention can perform multimedia decoding, hence the computer 60is not required to assist in the multimedia decoding calculation, thuspart of the north bridge 56 functions can be suspended or shut down; forexample, the north bridge 56 can suspended the bridging function amongthe south bridge 58, the CPU 52 and the memory 54, the north bridge canalso suspended managing the memory 54, yet only the image processingfunction is required to transmit the image data of the video port 82 tothe display unit 72 and to be displayed on the display unit 72;

Step 220: the CPU 52 sets the configuration of the south bridge 58 toshut down unnecessary functions, as known from FIG. 5 and other relateddiscussions, in the playback mode, the south bridge 58 can actually shutdown all its functions such as interrupt control, direct memory access(DMA) and other types of bus controls;

Step 222: the CPU 52 sets the mode of the micro-controller 64 such thatthe micro-controller 64 can convert the user's control on the controlinterface 66 into the control signal readable by the medium device 70;for example, a page-up key and a page-down key can be installed on thecontrol interface 66; when the computer system 50 operates in the normalmode, the two keys can act as a previous page and a next page keys for adocument processing program; but in the playback mode, after the settingof the micro-controller 64, the two keys can be converted into controlcommands of a previous chapter and a next chapter so that the user canutilize the two keys to control the chapters of the multimediabroadcast;

Step 224: the CPU 52 sets the back-end 78 of the medium device 70 sothat the back-end 78 begins operation;

Step 226: after setting for each related circuit and device iscompleted, the CPU 52 enters into a low power consumption idle status,or even stops operating; the back-end 78 of the medium device 70 beginsto perform the multimedia broadcast to manage the operations of thecomputer system 50 in the playback mode;

Step 228: start the playback mode to realize a low power consumptionmultimedia broadcast function.

As from the flow 200, when the computer system 50 of the presentinvention enters into the playback mode, the present invention not onlyshuts down part or all of the functions of the related circuit to lowpower consumption, but also it is not required to load the operatingsystem and its corresponding time-consuming steps, thus the playbackmode can be loaded quickly to provide a multimedia broadcast service tothe user. From the steps 218 to 228 of the playback mode, the steps torealizing the playback mode are mainly hardware settings steps whichdoes not require loading of the operating system, thus a more efficientmultimedia broadcast service can be prepared.

In determining the operation mode of the computer system of the presentinvention, other than the method of prompting selections for the user inthe flow 200, other methods can also be utilized. For example, thecomputer system 50 of the present invention can set different mode ofboot initializing mechanism on the control interface 66, such as thenormal mode has a corresponding normal mode switch, and the playbackmode also has a corresponding playback mode switch. If the normal modeswitch is pressed, the computer system 50 can directly perform the bootsequence of the normal mode (which is the steps 202, 204, 206, 208, 210,212, 214 and 216 of the flow 200); in contrary, if the playback modeswitch is pressed, the computer system can directly perform the bootsequence of the playback mode (which is the steps 202, 204, 206, 208,210, 218, 220, 222, 224, 226, and 228 of the flow 200).

From the discussion of FIG. 4 and FIG. 5, in a different mode, thecomputer 60 and the medium device 70 of the computer system 50 exchangedata through different paths. In the normal mode of FIG. 4, thefront-end 76 of the medium device 70 exchanges data with the southbridge 58 so that the CPU 52 accesses the storage medium in the mediumdevice 70 via the south bridge 58, the north bridge 56 and the front-end76. In the playback mode of FIG. 5, the back-end 78 of the medium device70 directly transmits the decoded image data and the audio data to thenorth bridge 56 and the audio codec 62 and the control signal isdirectly received by the micro-controller 64, therefore the bridging ofthe south bridge 58 is not required. To realize the above-mentionedmechanism of the present invention, the present invention utilizes asingle bus coupling to the computer 60 and the medium device 70 torealize the different data paths of the two modes; whether it is thenormal mode or the playback mode, the medium device 70 transmits therelated data and signal via the same bus. Please refer to FIG. 7, for acontinuation of the example from FIG. 3 through FIG. 5. FIG. 7illustrates an architecture of the computer system 50 utilizing a singlebus to realize a different data path at a different mode. As shown inFIG. 7, the computer 60 and the medium device 70 utilize and are coupledto a bus with a plurality of wires, for example, a bus that is IDEcompliant. A bus 90 is coupled to the south bridge 58 and an interfacecircuit 92 of the medium device 70, the interface circuit 92 is utilizedfor managing the accessing of the front-end 92 and the back-end 78 onthe bus 90. Furthermore, the front-end 76 and the back-end 78 can alsoutilize and are coupled to a bus that is compliant to the bus 90.

In order to support the different data path at the different mode, thebus 90 is coupled to the south bridge, and a set of wires G1 (whichincludes a plurality of wires) within the bus 90 is coupled to the videoport 82 of the north bridge 56 for becoming a data path for the imagedata during the playback mode. Similarly, another set of wires G2 (whichalso includes a plurality of wires) is coupled to the audio codeccircuit 62 via a switch circuit 94 for supporting the transmission ofaudio signals during the playback mode; in the normal mode, the switchcircuit 94 switches such that the audio codec circuit 62 couples to thesouth bridge 58. Furthermore, the bus 90 also includes a set of wires G3that is coupled to the micro-controller 64 via another switch circuit 96for transmitting the control signal of the micro-controller 64 to themedium device 70 in the playback mode; in the normal mode, the switchcircuit 96 switches such that the micro-controller 64 is coupled to thesouth bridge 58 so that the control signal of the micro-controller 64can be transmitted to the south bridge 58.

When the computer system 50 of FIG. 7 is operating in the normal mode,the back-end 78 of the medium device 70 is not required to operate, andthe interface circuit 92 allows the front-end 76 to be coupled to thebus 90; the bus control function of the south bridge 58 manages theoperation of the bus 90 so that the computer 60 can access the storagemedium via the bus 90 and the front-end 76. At this time, the northbridge 56 can stop receiving signals from the video port 82, the switchcircuit 94 controls the audio codec circuit 62 to receive theinformation data via the south bridge 58 (and not via the set of wiresG2), the switch circuit 96 then controls the micro-controller 64 totransmit the control signals to the south bridge 58 (and not via the setof wires G3) to function as a normal computer.

In contrary, when the computer system 50 is operating in the playbackmode, the back-end 78 of the medium device 70 decodes multimedia data toobtain image data and audio data. The interface circuit 92 allows theback-end 78 to access the sets of wires G1 to G3 on the bus 90. At thistime, the north bridge 56 activates the video port 82, and the imagedata of the back-end 78 is transmitted to the north bridge 56 via theset of wires G1 of the bus 90 so that the north bridge 56 can receiveand display the image data from the video port 82 on the display unit72. Similarly, the switch circuit 94 allows the audio codec circuit 62to access the set of wires G2 so that the audio data can be transmittedto the audio codec circuit 62 via the set of wires G2 and to bebroadcast through the loudspeaker 68. Otherwise, the switch circuit 98allows the micro-controller 64 to access the set of wires G3 so that themicro-controller 64 can directly transmit the control signal to themedium device 70 via the set of wires G3.

As known from FIG. 7 and other related discussions, even though a commonbus is utilized, the present invention can still form different datapaths at different modes. A continuation from the example from FIG. 7,please refer to FIG. 8. FIG. 8 is based on a IDE compliant bus as anexample to explain situations of the present invention utilizing asingle IDE bus 90 to realize different path at different mode. As shownin FIG. 8, an IDE bus interface (that is IDE compliant tonotebook/laptop computers) has 50 pins labeled from 1 to 50, 50 wiresare utilized to transmit each signal that is IDE compliant. In thenormal mode, the function of the bus 90 is to realize an IDE bus, thusthe function of each wire/pin is IDE compliant. For example in FIG. 8,in the normal mode, the pin of label 1 is utilized for transmittingaudio data of L-channel, pin of label 2 is utilized for transmittingaudio data of R-channel, each pin of label 6 to 21 is utilized fortransmitting data (e.g., signal Dnn, n=0, . . . n=15), other pins can beutilized to transmit related command of the IDE bus control or offsetvoltages (+5V, ground).

In the playback mode, the present invention can utilize each pin on theIDE bus to realize data paths of image data, audio data and a controlsignals. In the embodiment of FIG. 8, the present invention utilizes 8pins (wires) labeled 24, 25, 29, 32-36 to transmit image data (which issignal VDn, n=0, . . . ,7), the pin of label 37 is then utilized fortransmitting image data clock; in another words, the wires correspondingto the pins form the set of wires G1 of FIG. 7. As pins (pins that arelabeled 1-3) under the IDE standard are originally utilized fortransmitting audio data, thus the present invention can directly utilizethe pins to transmit the audio signals hence the set of wires G2 of FIG.7 is formed. As for the control signal, the present invention canutilize the undefined pins 49 and 50 of the IDE bus. Under the IDEstandard, the two pins are left unutilized for the manufacturers todefine. Thus the present invention can utilize the wires correspondingto the two pins to form the set of wires G3 of FIG. 7 so that thecontrol signal of the micro-controller is being transmitted to themedium device 70. In actual fact, as the two pins 49, and 50 are notutilized under IDE standard, thus in the embodiment of FIG. 7, themicro-controller 64 then does not require to set the correspondingswitch circuit 96, the micro-controller 64 itself is capable of directlytransmitting the control signal to the south bridge 58 and the set ofwires G3 simultaneously; in the normal mode, although the bus 90requires to the IDE bus function, but as the pins 49 and 50 are notdefined under the IDE standard, it does not affect the bus 90 being theIDE bus function. In the playback mode, the south bridge 58 can stopoperating and ignore the control signal transmitted from themicro-controller 64 to the south bridge 58.

In the playback mode, as the pins (e.g., number of wires) required bythe image data, the audio data and the control signal are less, thusthere are some pins (i.e., wires) in the bus 90 which is not utilized(as the blank in the form of FIG. 8 represents an unutilized pin).

Please note that the discussion in FIG. 7 and FIG. 8 is just oneembodiment of the present invention. The bus 90 of FIG. 7 can also be abus of other standard that is not limited to the IDE standard bus ofFIG. 8, and the definition of each pin (i.e., wire) in the playback modeis not limited by what is defined in FIG. 8. In actual fact, the presentinvention can apply different mode to different specific bus todistinguish different data path formed, and therefore there is norequirement to utilize a common bus like in FIG. 7.

As the medium device of the present invention itself has multimediadecoding functions, if the medium device is coupled to the computer(i.e., mainframe) in a insertion and extraction manner, not only can themedium device support the computer system to perform a low powerconsumption multimedia broadcast when coupled to the computer, and themedium device can also be an independent multimedia broadcasting devicewhen the medium device is pull out of the computer system. Please referto FIG. 9, with the example continued from FIG. 3. FIG. 9 illustrates adiagram of the medium device 70 becoming an independent broadcastingdevice according to the present invention. As shown in FIG. 9, themedium device 70 is coupled to the computer 60 through a connecting slot84, and an additional broadcast port 86 is installed to directly outputthe image data and the audio data decoded by the back-end 78. Anindependent control interface 98 can also be installed on the mediumdevice 70, the control interface 98 can include buttons, or even aremote control mechanism.

As shown in FIG. 9, when the medium device 70 of the present inventionis coupled to the computer 60 to form a computer system 50, the mediumdevice 70 can support the computer system 50 to operate in the normalmode and the playback mode (as described in FIG. 4 and FIG. 5). If themedium device 70 is pulled out of the computer 60, the back-end 78 ofthe medium device 70 can activate its multimedia decoding function andoutput the decoded image data and audio data via the broadcast port 86.The user can externally connect to a display unit 302 and a loudspeaker308 (e.g., a consumer TV or sound system), thus the medium device 70becomes an independent broadcast device for performing multimediabroadcast. In actual application, the user can control the operation ofthe medium device 70 via the control interface 98.

Also in the example of FIG. 9, the medium device 70 of the presentinvention can be applied in three kinds of situations. The firstsituation, the medium device 70 is coupled to the computer 60 forsupporting the computer system 50 to perform operations of the normalmode. In this situation, the back-end 78 can stop operating, the mediumdevice 70 is only utilized for supporting the accessing of the storagemedium; therefore the medium device 70 operates in a data mode only foraccessing the original data on the storage medium and not for performingdata decoding; the data is accessed by the front-end 76 and is outputtedby the medium device 70. The second situation is when the medium device70 is coupled to the computer 60, and the medium device 70 supports thecomputer system 50 to operate in a low power consumption multimediaplayback mode. In this situation, the back-end is activated forutilizing the display unit 72 and the loudspeaker 68 of the computersystem 50 to perform multimedia broadcast; the computer 60 itself is notrequired to perform multi-media decoding calculation. In another words,the image data and the audio data decoded by the back-end 78 areoutputted by the medium device 70. In the third situation, the mediumdevice 70 is an independent broadcasting device and is not coupled tothe computer 60. The back-end 78 is activated to perform multimediadecoding so that the user can directly operate consumer electronicproducts such as a display unit and a loudspeaker to perform multimediabroadcast. Even so, the medium device 70 can include a display unit anda loudspeaker which in the third situation the medium device 70 itselfcan perform multimedia broadcast.

In conclusion, in comparison to the conventional high power consumptionmultimedia broadcast computer system, the medium device of the computersystem of the present invention itself includes the multimedia decodingfunction, a normal mode with maximum functions and a low powerconsumption playback mode can be realized by combining with the chipsetof the present invention to suit the different requirements of the userin processing data and performing multimedia broadcast. Furthermore, themedium device itself can also be an independent multimedia broadcastingdevice to support different application situations by utilizing only thesame hardware architecture. Each circuit and device of the computersystem of the present invention can be realized by utilizing equivalentcircuits and devices; for example, the computer system of the presentinvention can be a notebook/laptop computer system or a desktop computersystem, the medium device can be a disc player for accessing an opticstorage medium, or a hard disk for magnetic storage medium, and themedium device can be a read-only device such as an electronicnon-volatile storage medium (such as a flash memory or memory card).

Those skilled in the art will readily observe that numerousmodifications and alterations of the device and method may be made whileretaining the teachings of the invention. Accordingly, the abovedisclosure should be construed as limited only by the metes and boundsof the appended claims.

1. A computer system capable of broadcasting multimedia data, thecomputer system comprising: a medium device comprises a front-end and aback-end, wherein the front-end is utilized for accessing multimediadata from a storage medium, and the back-end is utilized for decoding acorresponding image data from the multimedia data if the multimedia datafrom the storage medium accessed by the front-end is compliant to apreset multimedia format; and a chipset coupled to the medium device fortransmitting the image data obtained from decoding by the back-end to adisplay unit for displaying when the computer system operates in adefault playback mode.
 2. The computer system of claim 1 furthercomprising: a central processing unit (CPU) for controlling operationsof the computer, when the computer operates in the default playbackmode, the CPU stops operating.
 3. The computer system of claim 1 whereinif the computer is not operating in the default playback mode, theback-end stops operating and stops decoding the multimedia data.
 4. Thecomputer system of claim 1 further comprising: a loudspeaker coupled tothe chipset for broadcasting a corresponding audio data decoded from themultimedia data by the back-end, when the computer system is operatingin the default playback mode, the back-end decodes the multimedia datainto the corresponding audio data, and the chipset transmits the audiodata to the loudspeaker to be broadcast.
 5. The computer system of claim1 further comprising: a primary bridge coupled with the display unit, aCPU and a memory; and a secondary bridge coupled to the primary bridgeand the medium device; wherein when the computer system is operating inthe default playback mode, the primary bridge receives and transmits theimage data decoded by the back-end to the loudspeaker to be broadcast.6. The computer system of claim 5 further comprising: a controlinterface for receiving control operation of a user; and amicro-controller coupled to the control interface for providing acorresponding control signal according to the control operation receivedby the control interface, wherein when the computer system is operatingin the default playback mode, the micro-controller transmits the controlsignal to the medium device so that the front-end and the back-end ofthe medium device are being controlled by the control signal.
 7. Thecomputer system of claim 5 wherein the computer system further comprisesthe medium device coupled the chipset through an IDE bus, wherein whenthe computer system is operating in the default playback mode, theprimary bridge receives the image data decoded by the back-end via theIDE bus.
 8. The computer system of claim 1 wherein the computer systemfurther comprises a connecting port coupled with the medium device andthe chipset, when the medium device is not operating in the defaultplayback mode, the connecting port outputs the multimedia data accessedby the front-end, and when the medium device is operating in the defaultplayback mode, the back-end decodes to obtain the image data.
 9. Amedium device capable of connecting to a computer system, the mediumdevice comprising: a medium module for loading a storage medium; afront-end for controlling the medium module and accessing a multimediadata of the storage medium; and a back-end for decoding the multimediadata to obtain a corresponding image data when the medium device isoperating in a default playback mode, a primary bridge of the computersystem for displaying the image data within the computer system.
 10. Themedium device of claim 9 wherein the medium device further comprises aconnecting port coupled with the medium device and the primary bridge,when the medium device is not operating in the default playback mode,the connecting port outputs the multimedia data accesses by thefront-end, and when the medium device is operating in the defaultplayback mode, the back-end decodes to obtain the image data.
 11. Themedium device of claim 9 wherein the medium device is capable ofcoupling to a loudspeaker, when the medium device is operating in thepreset multimedia mode, an audio data obtained after decoding by theback-end is transmitted to the loudspeaker.
 12. The medium device ofclaim 9 wherein the medium device is not operating in the defaultplayback mode, the back-end is capable of stopping operation to stopdecoding the multimedia data.
 13. The medium device of claim 9 whereinthe medium device is a compact disc, a flash memory or a hard disk. 14.The medium device of claim 9 wherein the preset multimedia format is anMPEG1, MPEG2 or MPEG4 format.
 15. The medium device of claim 9 whereinthe computer system is a laptop computer.
 16. A computer system capableof performing multimedia broadcast, coupled to a medium device, thecomputer system comprising: a display unit for broadcasting an imagedata decoded by a back-end within the medium device; and a primarybridge coupled to the display unit for transmitting the image datadecoded by the back-end of the medium device to the display unit. 17.The computer system of claim 16 wherein the computer system furthercomprises a connecting port coupled with the back-end of the mediumdevice and the primary bridge, the connecting port outputs the imagedata decoded by the back-end to the primary circuit.
 18. The computersystem of claim 16 wherein the primary bridge transmits a sound datadecoded by the back-end of the medium device to a loudspeaker forbroadcasting sound.
 19. A computer system capable of broadcastingmultimedia data, coupled to a medium device, the computer systemcomprising: a display unit for displaying an image data; a primarybridge coupled to the medium device and the display unit fortransmitting the image data decoded by a back-end of the medium deviceto the display unit to be displayed when the computer system isoperating in a default playback mode; a secondary bridge coupled to themedium device and the primary bridge for transmitting the image datadecoded by a front-end of the medium device to the primary bridge whenthe computer system is not operating in the default playback mode, andthe primary bridge transmits the image data to the display unit; and aCPU coupled to the primary circuit for controlling operations of thecomputer system, when the computer system is operating in the defaultplayback mode, the CPU stops operating, and when the computer system isnot operating in the default playback mode, the CPU operates.
 20. Thecomputer system of claim 19 wherein when the computer system is notoperating in the default playback mode, the back-end stops operating andstops decoding the multimedia data.
 21. The computer system of claim 19further comprising: a loudspeaker coupled to the secondary bridge andthe primary bridge for broadcasting a corresponding audio data decodedby the back-end, when the computer system is operating in the defaultplayback mode, the back-end decodes the multimedia data to obtain thecorresponding sound data and the audio data is transmitted to theloudspeaker to be broadcast.
 22. The computer system of claim 19 whereinthe computer system further comprises a memory coupled to the primarybridge for temporarily storing the image data.
 23. The computer systemof claim 19 further comprising: a control interface for receivingcontrol operation of a user; and a micro-controller coupled to thecontrol interface for providing a corresponding control signal accordingto the control operation received by the control interface, wherein whenthe computer system is operating in the default playback mode, themicro-controller transmits the control signal to the medium device sothat the front-end and the back-end of the medium device are beingcontrolled by the control signal.
 24. The computer system of claim 19wherein the computer system further comprises the medium device coupledto the primary bridge through an IDE bus, wherein when the computersystem is not operating in the preset multimedia mode, the secondarybridge transmits the image data accessed by the front-end via the IDEbus, and when the computer system is operating in the default playbackmode, the primary bridge receives the image data decoded by the back-endvia the IDE bus.
 25. The computer system of claim 19 wherein thecomputer system further comprises a connecting port coupled with themedium device, the primary bridge and the secondary bridge, when themedium device is not operating in the default playback mode, theconnecting port outputs the multimedia data accessed by the front-end,and when the medium device is operating in the default playback mode,the back-end decodes to obtains the image data.
 26. A method ofbroadcasting multimedia data on a computer system, the computer systemcomprising a medium device and a computer, the medium device beingcoupled to the computer through a connecting port, wherein the mediumdevice comprises a back-end and a front-end, and the computer comprisesa primary bridge, a secondary bridge, a CPU and a display unit, themethod comprising: determining whether the computer system is operatingin a default playback mode; the back-end within the medium devicedecoding the multimedia data if the computer system is operating in thedefault playback mode, and the primary bridge of the computertransmitting the decoded multimedia data to the display unit of thecomputer to be displayed; and the front-end within the medium devicetransmitting the multimedia data from the secondary bridge of thecomputer to the primary bridge if the computer system is not operatingin the default playback mode, and the front-end transmitting themultimedia data to the display unit of the computer via the CPU to bedisplayed.
 27. The method of claim 26 wherein the computer system is notoperating in the default playback mode, the back-end stops operating andstops decoding the multimedia data.
 28. The method of claim 26 furthercomprising: decoding the multimedia data corresponding to an audio dataand outputting the audio data to a loudspeaker to be broadcast if thecomputer system is operating in the default playback mode.
 29. Themethod of claim 26 wherein the secondary bridge transmits the multimediadata accessed by the front-end to the primary bridge when the computersystem is not operating in the default playback mode, and the primarybridge is a transmission medium among the CPU, the memory and thesecondary bridge for transmitting the multimedia data to the memory orthe CPU.
 30. The method of claim 26 wherein the primary bridge is not atransmission medium among the CPU, the memory and the secondary bridgewhen the computer system is operating in the default playback mode, andthe primary bridge receives and transmits the image data decoded by theback-end to the display unit to be displayed.
 31. The method of claim 26further comprising: the secondary bridge receiving the multimedia dataaccessed by the front-end through an IDE bus when the computer system isnot operating in the default playback mode; and the primary bridgereceiving the image data decoded by the back-end through the IDE buswhen the computer system is operating in the default playback mode. 32.A method of broadcasting multimedia data on a computer system, thecomputer system comprising a medium device and a computer, the mediumdevice being coupled to the computer through a connecting port, whereinthe medium device comprises a back-end and a front-end, and the computercomprises a primary bridge and a display unit, the method comprising:the back-end of the medium device decoding the multimedia data; and theprimary bridge of the computer transmitting the decoded multimedia datato the display unit of the computer to be displayed.
 33. The method ofclaim 32 further comprising: decoding the multimedia data correspondingto an audio data and outputting the audio data to a loudspeaker to bebroadcast if the computer system is operating in the default playbackmode.
 34. The method of claim 32 further comprising: the primary bridgereceiving an image data decoded by the back-end through an IDE bus.